風力規範之標準地況分類與紊流邊界層特性研究

Investigations on the Terrain Classification and Characteristics of Atmospheric Turbulent Boundary Layer

我國建築物耐風設計規範中，風場特性為參考ASCE-7 相關規定所訂定。然而我國設計風速主要受颱風影響，與美國大陸型氣候不盡相同。ASCE-7 地況分類標準未必能正確地反應本土的地況分類及風場特性，須進一步探討耐風設計規範中標準地況的分類標準以及應用自然風場之實場監測以驗證之。本研究透過文獻回顧、國內外風力規範之整理及風洞模擬，對於自然風場的地況分類標準提出修正建議。此外本文在淡水濱海地區建立邊界層特性的實場監測站，取得颱風與東北季風的實測數據並提出颱風實測數據的分析方法與包括平均風速垂直分佈剖面、紊流特性、陣風因子等重要風場特性，可供未來風力規範修正之參考。

This paper investigates the terrain classification and the wind characteristics of the strong wind defined in the building wind code. Since the nature of complex terrain and city types in Taiwan are quite different from those in US, the terrain classification in the current building wind code may be different from ASCE7-02. Therefore, it is most urgent that these distinct local characteristics are accurately reflected in the building wind code. Based on the literature review and comparative study on several national wind codes, a set of classification standards for the terrain categories is proposed. The data analysis procedure for the random in-situ data is also introduced. Results from the field measurement indicate that the mean velocity gradient obtained from the field is higher than expected and the absolute mean wind speed cast only minor effect on the turbulence. Based on the in-situ data, a set of turbulence parameters and empirical Harris-Karman type spectra are recommended.